Field of the Invention
The present invention relates to an imaging device and an imaging system.
Description of the Related Art
A stacked imaging device is known, the device including photoelectric conversion elements stacked on a semiconductor substrate, the each elements including pixel electrode, photoelectric conversion layer and common electrode formed in this order. Japanese Patent Application Laid-Open No. 2011-249677 describes a configuration of reducing the impedance of the common electrode by forming a conductive film on the common electrode in order to reduce a signal output difference between near the center and near the periphery of an imaging region caused by resistance values of the common electrode of photoelectric conversion elements.
In the imaging device described in Japanese Patent Application Laid-Open No. 2011-249677, a grid-like or matrix-like conductive film is formed on the photoelectric conversion elements. The conductive film may block light or reduce the transmittance of light, and the sensitivity of incident light may be reduced if the area of the conductive film is increased. Therefore, increasing the area of the conductive film is difficult in the imaging device described in Japanese Patent Application Laid-Open No. 2011-249677, and sufficiently reducing the impedance of the common electrode is difficult. As a result, a signal output difference may be generated between near the center and the near the periphery of the imaging region, and the image quality may be deteriorated.